If they had faced all of the Skolasi Empire's remaining fleets at once, the Alliance would indeed have suffered considerable losses, at least on the scale of 500 legions.
But if they were only facing less than a third of those fleets, their own losses would drop to a tenth of that—or perhaps even less.
The Imperial fleet stationed at the passage entrance consisted of only 3,000 Main Legions and 5,000 Guard Legions.
Meanwhile, the Alliance had 5,000 legions, and even the Alliance's standard fleets were stronger than those of the Skolasi Empire, not to mention the considerable number of Federation Superpower Fleets.
The massive disparity in combat strength, coupled with the low morale of the Imperial soldiers, caused the defensive line formed by 8,000 legions to collapse completely in barely half a day.
In fact,
the Alliance had only just passed through the passage, with merely 2,000 legions having arrived.
The entire process went even more smoothly than Montero had anticipated.
Because the defending forces had collapsed too quickly, neither the 6,000-legion reserve fleet nor the 16,000 legions stationed at the other two locations had time to rush over in support.
The Empire's fleet commander was not entirely foolish either. Rather than continuing to order those three fleets to reinforce the battle, he had them abandon their support missions and assemble instead.
In terms of cruising speed within the black cavity, the Federation did not actually hold much of an advantage over a Peak Fifth-order civilization.
Therefore, stopping them from assembling, or intercepting and eliminating one force before they could gather, was somewhat unrealistic.
But that did not matter. From the very beginning, Montero had never expected the enemy to do something so foolish as keep sending reinforcements one group at a time to their deaths.
Go ahead and